sclass DownloadedMedia {
  S cmd;
  Map info;
  File convertedFile;
  
  *(S *cmd, S json, S convertedExtension) {
    info = jsonDecodeMap(json);
    convertedFile = replaceExtension(get(), convertedExtension);
  }
  
  File mediaFile aka get() {
    if (convertedFile != null) ret convertedFile;
    ret newFile((S) info.get("_filename"));
  }
  
  O get(S key) { ret info.get(key); }
  
  toString { ret "DownloadedMedia: " + renderFileInfo(mediaFile()); }
  
  Map toMap() { ret info; }
}